阅读说明：本技术 功率转换装置 (Power conversion device ) 是由 坂本达朗 于 2018-04-09 设计创作，主要内容包括：本发明提供一种功率转换装置，是具备绝缘变压器的功率转换装置，绝缘变压器包括：初级绕组；次级绕组；以及磁屏蔽部，该磁屏蔽部通过阻断在初级绕组和次级绕组中分别流过的电流所产生的磁通来抑制初级绕组与次级绕组之间的磁干扰。磁屏蔽部例如由设置在初级绕组与次级绕组之间的磁屏蔽板构成。(The present invention provides a power conversion device provided with an insulation transformer, wherein the insulation transformer comprises: a primary winding; a secondary winding; and a magnetic shield portion that suppresses magnetic interference between the primary winding and the secondary winding by blocking magnetic fluxes generated by currents flowing in the primary winding and the secondary winding, respectively. The magnetic shield portion is constituted by, for example, a magnetic shield plate disposed between the primary winding and the secondary winding.)

1. A power conversion device having an insulation transformer, characterized in that,

the insulation transformer includes:

a primary winding;

a secondary winding; and

a magnetic shield portion that suppresses magnetic interference between the primary winding and the secondary winding by blocking magnetic fluxes generated by currents flowing in the primary winding and the secondary winding, respectively.

2. The power conversion apparatus according to claim 1,

the power conversion device further includes a case that houses components of the power conversion device,

the magnetic shield portion is connected to the case.

3. The power conversion apparatus according to claim 1,

the power conversion device further includes a heat sink that cools components of the power conversion device,

the magnetic shield portion is connected with the heat sink.

4. The power conversion apparatus according to any one of claims 1 to 3,

the magnetic shield portion is configured by a magnetic shield plate arranged between the primary winding and the secondary winding.

5. The power conversion apparatus according to any one of claims 1 to 3,

the insulation transformer is an insulation transformer with a center plug mode on a secondary side, and the secondary winding comprises a first secondary winding and a second secondary winding.

6. The power conversion apparatus of claim 5,

the primary winding is formed by a winding layer divided into at least two layers,

the first secondary winding and the second secondary winding are arranged between the winding layers, and when the primary winding is in a conductive state, one of the first primary winding and the second secondary winding is in a conductive state, and the other is in a non-conductive state,

the magnetic shielding portion is configured by one of the first secondary winding and the second secondary winding which is in the non-conductive state.

7. The power conversion apparatus according to any one of claims 1 to 6,

the number of the primary windings and the number of the secondary windings are more than one.

8. The power conversion apparatus according to any one of claims 1 to 7,

the number of turns in either the primary winding or the secondary winding is greater than 1.

9. The power conversion apparatus according to any one of claims 1 to 8,

the constituent elements of the power conversion apparatus include semiconductor switching elements,

the semiconductor switching element is an element formed of a wide bandgap semiconductor.

10. The power conversion apparatus of claim 9,

the wide band gap semiconductor is a semiconductor using silicon carbide, a gallium nitride-based material, or diamond.

Technical Field

The present invention relates to a power conversion device provided with an insulation transformer.

Background

An insulated power converter capable of electrically separating input and output is widely used between systems, power supplies, and the like (see, for example, patent document 1). For example, in recent years, electric vehicles such as electric vehicles and plug-in hybrid vehicles have been developed. In such an electric vehicle, an insulated power converter is used as an in-vehicle charger for charging a high-voltage battery from a household power supply. Such power conversion devices are often required to be miniaturized to improve load-carrying performance for electric vehicles.

An insulation transformer is used in an insulation type power conversion device to achieve electrical separation and voltage conversion between a power supply on an input side and a load on an output side. An insulation transformer is composed of an iron core (also referred to as a transformer core) containing iron as a main component, and a primary winding and a secondary winding wound around the iron core. In the insulation transformer, the number of turns of the primary winding and the number of turns of the secondary winding are set to correspond to a target transformation ratio, respectively.

In general, a method for realizing miniaturization of a power conversion apparatus is to use a method of increasing a switching frequency of a switching element. This is because increasing the switching frequency can reduce the voltage-time product (VT product) of the insulating transformer and the loss (core loss) of the core, and as a result, the core can be made smaller.

However, as the switching frequency increases, the skin effect, the magnetic interference between the primary and secondary windings (proximity effect) causes the resistance value of the winding to increase, resulting in an increase in the loss of the winding (copper loss). In this case, the temperature of the winding increases as the copper loss increases. Since the temperature of the winding is set so as not to exceed the upper limit of the temperature of the winding, it is necessary to increase the cross-sectional area of the winding to reduce the winding loss or to provide a cooling mechanism for the winding, which results in an increase in the size of the insulation transformer.

Disclosure of Invention

Technical problem to be solved by the invention

As described above, the power conversion apparatus needs to be further miniaturized, and for this reason, the insulation transformer as a main component must be miniaturized. In order to miniaturize the insulation transformer, the switching frequency of the switching element needs to be increased. However, as the switching frequency increases, both the resistance value of the winding and the loss of the winding increase, thereby limiting the miniaturization of the insulation transformer.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power conversion device that is miniaturized by improving the structure of an insulation transformer.

Technical scheme for solving technical problem

The power conversion device of the present invention is a power conversion device provided with an insulation transformer, the insulation transformer including: a primary winding; a secondary winding; and a magnetic shield portion that suppresses magnetic interference between the primary winding and the secondary winding by blocking magnetic fluxes generated by currents flowing in the primary winding and the secondary winding, respectively.

Effects of the invention

According to the present invention, a power conversion device that can be miniaturized can be obtained by improving the structure of the insulation transformer.

Drawings

Fig. 1 is a schematic configuration diagram of a power conversion device in embodiment 1 of the present invention.

Fig. 2 is a timing chart showing an example of time changes of control signals for controlling the semiconductor switching element of fig. 1, a primary winding voltage and a secondary winding voltage of the insulating transformer, a core magnetic flux density of the insulating transformer, and a voltage and a current of the filter reactor.

Fig. 3 is an explanatory diagram showing an example of a frequency spectrum of a current flowing through the primary winding of the insulation transformer of fig. 1.

Fig. 4 is an explanatory diagram showing an example of frequency characteristics of the resistance value of the primary winding of the insulation transformer of fig. 1.

Fig. 5 is a structural diagram showing an example of the structure of an insulation transformer in embodiment 1 of the present invention.

Fig. 6 is a configuration diagram of a magnetic shield plate of an insulation transformer in embodiment 1 of the present invention.

Fig. 7 is a schematic configuration diagram of a power conversion device in embodiment 2 of the present invention.

Fig. 8 is a structural diagram showing an example of the structure of an insulation transformer in embodiment 2 of the present invention.

Fig. 9 is a timing chart showing an example of a control signal for controlling the semiconductor switching element of fig. 7, a current flowing through each of the primary winding, the first secondary winding, and the second secondary winding of the insulation transformer, and a time change of a current flowing through the filter reactor.

Detailed Description

Hereinafter, a power conversion device according to the present invention will be described according to a preferred embodiment with reference to the drawings. In the description of the drawings, the same or corresponding portions are denoted by the same reference numerals, and redundant description is omitted.